Optimal Resolution Level for Input–Output Control of $3\phi$ VS WM AC–DC Converters

The switching pulses of the wavelet modulation technique are generated as sets of dilated and shifted scale-based linearly combined synthesis wavelet functions. The duration and location of each switching pulse are set by the scale (resolution level) at which its associated synthesis wavelet function is generated. In this paper, a novel controller is developed and tested for three phase (3φ) voltage source (VS) six-pulse wavelet-modulated ac-dc converters. The proposed controller is structured to adjust the maximum value reached by the scale. This maximum value, J, is adjusted based on two angles. The first angle, θ
_I
, maps changes in the 3φ supply voltages to adjustments in J, while the second angle, θ
_O
, maps changes in the dc output voltage to adjustments in J. The net adjustment in J is optimized based on the mapped changes by θ
_I
and θ
_O
. The optimal resolution-level controller is implemented in order to evaluate its performances for operating 3φ VS six-pulse ac-dc converters. The performances of the proposed controller are tested when the converter is supplied with balanced, unbalanced, and distorted 3φ voltages for feeding static and dynamic loads. Test results demonstrate fast and accurate responses, stable functioning, and good dynamics to ensure that the output dc voltage follows its command value for different supply and loading conditions.